Many applications which process data-centric XML do that based on a nice specification, expressed in an XML Schema. XML::Compile reads and writes XML data with the help of such schema's. On the Perl side, it uses a tree of nested hashes with the same structure. Where other Perl modules, like SOAP::WSDL help you using these schema's (often with a lot of run-time (XPath) searches), this module takes a different approach: in stead of run-time processing of the specification, it will first compile the expected structure into real Perl, and then use that to process the data. There are many perl modules with the same as this one: translate between XML and nested hashes. However, there are a few serious differences: because the schema is used here, we make sure we only handle correct data. Data-types are formatted and processed correctly; for instance, integer does accept huge values (at least 18 digits) as the specification prescribes. Also more complex data-types like list, union, and substitutionGroup (unions on complex type level) are supported, which is rarely the case in other modules. WWW: http://search.cpan.org/dist/XML-Compile/